corrections in FIVE vs peak info

[Harry Moore]

Hello,

I've noticed that when visualising some overlays in FIVE that sometimes when I apply an FWE or FDR correction FIVE corrects the uncorrected p value, and also alters the activated voxels in the overlay, but when I either select Options > Get Peak Info, or run peak_nii, the 'sigthresh' variable does not contain any values and therefore leads me to conclude that there are actually no voxels that survive the FWE or FDR correction - so am I right in trusting the sigthresh result rather than the uncorrected p value when I press FWE/FDR in the FIVE viewer?

Thanks

[Aaron Schultz]

I will leave it to Donald to answer definitively, but the main difference will have to do with voxel wise corrections vs cluster wise corrections. 

-Aaron

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[H M]

Hi again Aaron,

I have been looking at the 'voxelstats' variable created by peak_nii and 'get peak info' in FIVE to get around this problem, and I understand that when I apply an FDR correction in FIVE/peak_nii it calculates the uncorrected p value necessary to meet the FDR threshold (in my case 0.05). But when looking at the output variable 'voxelstats', although the uncorrected p value column matches up with what I expected the uncorrected p values to be at an FDR threshold of 0.05, I expected the q value column to only have values of 0.05 and lower, which is not the case. It's no unlikely that I've misunderstood the theory behind the correction, but do you think that makes sense? (for example,  the uncorrected p value for FDR = 0.05 was set to 0.002, which was the highest value in the uncorrected p value column in 'voxelstats' and its corresponding q value was 0.49)

Cheers

On Tuesday, 22 October 2019 16:36:51 UTC+1, Aaron Schultz wrote:

I will leave it to Donald to answer definitively, but the main difference will have to do with voxel wise corrections vs cluster wise corrections. 

-Aaron

On Tue, Oct 22, 2019 at 4:20 AM Harry Moore <htam...@gmail.com> wrote:

Hello,

I've noticed that when visualising some overlays in FIVE that sometimes when I apply an FWE or FDR correction FIVE corrects the uncorrected p value, and also alters the activated voxels in the overlay, but when I either select Options > Get Peak Info, or run peak_nii, the 'sigthresh' variable does not contain any values and therefore leads me to conclude that there are actually no voxels that survive the FWE or FDR correction - so am I right in trusting the sigthresh result rather than the uncorrected p value when I press FWE/FDR in the FIVE viewer?

Thanks

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